Dilute nitride long wavelength semiconductor diode lasers

This thesis studies the novel dilute nitride semiconductor materials, GaInNAs and GalnNAsSb, and their usage in GaAs-based diode lasers emitting between 1.25 to 1.55 mum in wavelength. This work covers material physical modeling, laser simulations, design and the experimental work of device characterization. The tabulated band anti-crossing theory of the quaternary GaInNAs is formulated. The resulting formulas are further corrected by our experimental observations. This modified band anti-crossing theory is implemented into the commercial laser simulator Las2D. Together with other electrical and optical models equipped with the unique GaInNAs parameters, Las2D becomes the first simulator that calculates the operational behavior of dilute nitride lasers. A two-dimensional simulation algorithm is discovered using the samples of ridge waveguide GalnAs/GaAs lasers that emit at 1.0 mum in wavelength. This algorithm is used in the calibration of the Las2D simulator for dilute nitride lasers. Using the calibrated simulator, several optimized quantum well designs for high-speed, temperature-insensitive devices are suggested with special considerations on the carrier uneven distributions in quantum wells and the nitrogen-induced gain reduction that occurs in dilute nitride material. Fabry-Perot cavity, ridge waveguide lasers emitting at 1275 nm were fabricated by molecular beam epitaxy using a double quantum well GaInNAs (well)---GaAs (barrier) structure. A complete set of static and dynamic characterizations were carried out on those lasers to evaluate dilute nitride material properties as an active media. The temperature dependent light-current (L-I) measurements demonstrated a temperature insensitive device with a characteristic temperature as high as 155 K. Although challenges in material quality remain, the lasers show lasing properties similar to conventional GaAs- and InP-based lasers with respect to the transparency current (6 mA), the material gain (1000 cm -1), the optical loss (7 cm-1), the beam quality (single transverse mode operation, 2.8 in linewidth enhancement factor, 0.55 nm/K in the rate of spectral temperature shift), and the maximum modulation bandwidth (9.7 GHz). The GaInNAsSb QW structure allows the further extension of the laser emitting wavelength to the desired 1.55 mum range. Although the quantum wells and the nitrogen-content barrier challenge the crystal growth, a room temperature, continuous-wave operating GaInNAsSb (quantum well)---GaNAs (barrier) laser was demonstrated for the first time with a record long operating wavelength (1553 nm) for GaAs-based lasers. L-I measurements were carried out on those lasers. The laser optical gain and loss properties were studied using the unique cavity loss dependent analysis